
12-9
IM 704610-01E
Troubleshooting and
Maintenance
12
12.5 Calibration (Changing the Factory Default
Calibration Values)
Procedure
MEDIA
FUNCTION
POLARITY
ARMING
INHIBIT
LOCAL
RECALL
ENTER
TRIG
IMPEDANCE EQUALIZER
SEC RANGE
KEY
LOCK
MEASURE
DISP OFF
JUDGE
GO
NO-GO
10%
20%
S
SEC RANGE
SCALE
L.MARK
R.MARK
GATE TIME
DELAY
BLOCK
REMOTE
STORE
UTILITY
JDG LEVEL
LEVEL
AUTO
COUPLE
EQ BOOST
MAN
CONV
50
Ω
1M
Ω
PW
E2T
D to C
BD x1
ns ms
s
%
V
%/
S
SHIFT
SHIFT
Display 1
Display 2
POWER
Note
When calibration completes normally, new calibration values are obtained. To apply the
calibration values obtained through this operation, you must change the factory default
calibration values. If you change the factory default calibration values, you cannot undo the
changes. Please confirm that it is okay to change the factory default calibration values
beforehand. Note that initialization (see section 11.2) will not set the calibration value back to
factory default.
The operations mentioned below should be carried out in the following cases:
• When the allowable range is exceeded in the performance test described in
section 12.6.
• When parts of the TA220 have been replaced.
Before starting calibration, remove all cables connected to the instrument (both
input and output) other than the power cable and communication cable. Make
sure that the TA220 is not in remote mode at this point.
For the procedure in switching from remote mode to local mode, see section 8.2 or section
9.1.
Starting in Maintenance Mode
1.
Check that the power switch is turned OFF.
2.
Hold down SCALE and turn ON the power switch (press POWER ). Hold
SCALE down for approximately three seconds. When the power switch is turned
ON, the model name and results of each test are displayed on Display 2 (model
name -> EQ board -> MEMORY -> ETHER, and so on). At this point the
instrument enters maintenance mode, and TESTMODE is displayed on Display
2.
Let the TA220 warm up for at least thirty minutes in this condition.